1. Field of the Invention
The present invention relates to lighting fixtures and, more particularly, to adjustment mechanisms for luminaire-type lighting fixtures.
2. Description of the Related Art
Wall mounted luminaire-type lighting fixtures are often designed to be tiltably adjusted. However, current luminaire adjustment mechanisms tend to be difficult to use. Current adjustment mechanisms often employ exterior rotatable knurled knobs that tend to be obtrusive and require that the luminaire be spaced from the wall in order to accommodate the adjustment mechanism. Some of these adjustment mechanisms also employ lubricating grease within its workings, which can produce an unsightly residue on and around the lighting fixture. Set screws or lock washers are often included in these current adjustment mechanisms to lock in place the optical housing of the fixture after adjustment. The use of such securing means requires multiple steps in adjusting and locking the fixture. They also often lead to imprecise adjustment, due to the tendency of the lighting fixture to shift as the securing means is tightened.
Thus, there is a need for an adjustment mechanism for a luminaire that provides for easy and precise adjustment, and is less obtrusive than current mechanisms. The novel adjustment mechanism should provide for the precise adjustment of the fixture by the use of a socket driver or other similar tool, without soiling the fixture. The mechanism should also maintain the luminaire in position once it has been so adjusted.
It is an object of the present invention to provide an adjustment mechanism for a luminaire.
It is another object of the present invention to provide an adjustment mechanism for a luminaire that allows for the adjustment and securing into position of a luminaire with one movement.
It is yet another object of the present invention to provide an adjustment mechanism for a luminaire that is cleaner and less obtrusive than many current mechanisms.
It is a further object of the present invention to provide an adjustment mechanism having a floating adjustment bolt that allows for the adjustment of the fixture along an arcuate path.
More particularly, an adjustment mechanism of the present invention includes a mounting bracket that attaches the lighting fixture to a wall, pole or similar structure. The mounting bracket includes a substantially arcuate support wall that includes at least one, and preferably three slots therein. An adjustment brace is also provided, which is fastened to the optical housing of the lighting fixture by at least one fastening means, such as a housing bolt. The fastening means, or housing bolt, is preferably disposed in one of the slots included in the mounting bracket, and is free to move along the course of the slot, thereby allowing the adjustment brace and the optical housing to move relative to the mounting bracket. Attached to the adjustment brace is a non-rotatable threaded nut, through which a threaded adjustment bolt is received. The non-rotatable nut is free to move along at least a portion of the threaded length of the adjustment bolt, as the adjustment bolt is axially rotated. The shaft of the adjustment bolt is also disposed through a positioning means, such as an eyebolt, which is attached to the mounting bracket. At least one securing means, such as a washer, nut or combination of both, is attached to the adjustment bolt. The securing means restricts the movement of the adjustment bolt so that the bolt remains in position as the non-rotatable bolt moves along its shaft.
In use, the optical housing may be adjusted relative to the mounting bracket by axially rotating the adjustment bolt, preferably with a socket driver or other similar tool. As the adjustment bolt is rotated, a mechanical advantage is gained by the presence of the positioning and securing means, which act to restrict the movement of the bolt. More specifically, the adjustment bolt remains in position as it is turned, while the non-rotatable nut is able to move along the shaft of the rotating bolt. The adjustment and optical housing brace move with the non-rotatable nut. The adjustment bolt has enough room to shift within the eyelet of the eyebolt, so that the shaft""s angle of inclination shifts with the non-rotatable nut as the nut and the adjustment brace move along the arched support wall of the mounting bracket. Also, the non-rotatable nut is movably attached to the adjustment brace so that the nut may xe2x80x9cfloatxe2x80x9d as it moves along the arched support wall. The housing bolts connecting the optical housing to the adjustment brace move, in conjunction with the adjustment brace, along the slots of the mounting bracket. The optical housing, in turn, moves, along the same arc, defined by the support wall of the mounting bracket, as the housing bolts do, thereby providing for the adjustment of the light emanating from the optical housing. When the optical housing has been adjusted to the desired position, the fixture may be locked into position simply by stopping the rotation of the adjustment bolt. The frictional interaction of the thread of the non-rotatable nut and the thread of the adjustment bolt prevent any further movement of the optical housing.
It will become apparent that other objects and advantages of the present invention will be obvious to those skilled in the art upon reading the detailed description of the preferred embodiment set forth hereinafter.